No abstract

Colombia is a country for which one of the highest biodiversity rates is reported, and one of the first in the tropical areas where an effort was made to gather information on indigenous fungi. Nevertheless, mycological data are still scarce and discontinuous, above all on soil fungi. The present study wanted to contribute to unveil the large soil fungal biodiversity in the upper Andean Colombian agro-ecosystems. The studied area is located in the department of Boyacà, considered with a notable economical value, partly devoted to subsistence agriculture. More than 150 described species were revealed in this study, belonging to 5 phyla with Ascomycota representing the dominant taxon. Basidiomycota and Zygomycota are also well represented, dominated by species of the genus Sebacina and Mortierella respectively, mainly distributed in the semi-natural plots (woodland and grassland). Most of the species are reported as first records for Colombia. Some of them are particularly interesting for their conservation significance such as Geoglossum fallax , which is the dominant species in the unimproved grassland plot. The bootstrap-based clustering analysis showed a different distribution of the species in orchards and non-cultivated areas as a possible response of the fungal community to different use of soil in the agro-environment.

Pesticides can help reduce yield losses caused by pests, pathogens, and weeds, but their 22 overuse causes serious environmental pollution. They are persistent in the environment and 23 are biomagnified through the food chain, becoming a serious health hazard for humankind. 24 Bioremediation, where microbes are used to degrade pesticides in situ, is a useful technology. 25 This review summarizes data on the fungi involved in the biodegradation of chemical 26 pesticides; and their application in soil and water bioremediation. Indications for future 27 studies in this field are given.

Although Colombia was one of the first tropical countries where an effort was made to gather mycological flora, contributions to the taxonomy, diversity, and ecology of soil microfungi are still scarce. In this study, the diversity of soil microfungi was studied collecting data from literature according to the Colombian natural regions: Andean, Amazonian, Caribbean, Orinoquía, Pacific, and Insular. The majority of the records comes from the Andean region, the most accessible to research. The other regions have been much less studied, with the Insular one with no data at all. International literature reported, up to now, ca. 300 different species of soil microfungi belonging to 126 different genera and 6 phyla (Ascomycota, Basidiomycota Mucoromycota, Glomeromycota, Mortierellomycota, and Olpidiomycota). Vescicular-Arbuscular fungi were widely investigated with Acaulospora and Glomus, the most recorded genera with ca. 20 species each. Ascomycota was the most diverse phylum with Penicillium, Aspergillus, and Fusarium representing the majority. Mortierella is strongly present in Mortierellomycota, and in the panorama of all recorded fungi, too. The other phyla and genera were less recorded. It is, therefore, evident the need to continue studying the soil microfungi in Colombia to have a better understanding of soil functioning and its ecosystem services.

Plant material obtained by pruning and production of deciduous fruit trees was evaluated as substrates for the production of the oyster mushroom, Pleurotus ostreatus . Lignified branches and stems from peach, apple, and pear trees were processed using a ripping machine to reduce the size of chips and to optimize disinfection. A completely randomized experimental design was proposed with six treatments (novel substrates) and one absolute control (100% hay substrate). Morphological variables such as thickness and diameter of the pileus, stipe length were assessed, as well as production variables (sprouting, fresh weight, and biological efficiency) and bromatological analysis (ash, ethereal extract, crude fiber, and crude protein). Apart from the 100%-hay substrate, biological efficiency ranged between 27% (100% apple tree as the substrate) and 140% (50% hay + 50% peach tree as the substrate). According to morphological analysis, the highest diameters were recorded from mixed substrates (50% hay + 50% wood), and a highly significant positive correlation was found between diameter and stipe length. Morphological parameters were not significantly correlated with biological efficiency. Analysis of biological efficiency confirmed that mixed substrates clustered together with 100%-wood substrates. Bromatological analysis showed that the mixed substrate (50% hay + 50% pear tree) had the highest protein content among the novel tested substrates. Bromatological parameters were not significantly correlated with biological efficiency. In conclusion, pruning residues from fruit trees can be valuable by using them as substrates for the cultivation of P. ostreatus . Production is quantitatively competitive with that using hay, on the condition that wood is mixed with hay.

In Colombia, the cultivation of deciduous fruit trees such as pear is expanding for socio-economic reasons and is becoming more and more important for the local population. Since organized cultivation is slowly replacing sustenance cultivation, scientific information on the present agro-environment is needed to proceed in this change in an organic and environmentally friendly way. In particular, this study is an accurate description of the mycobiota present in the bulk soil of two different high altitude pear orchards in the Colombian Andes. The metabarcoding of soil samples allowed an in-depth analysis of the whole fungal community. The fungal assemblage was generally dominated by Ascomycota and secondly by Mortierellomycota. As observed in other studies in Colombia, the genus Mortierella was found to be especially abundant. The soil of the different pear orchards appeared to host quite different fungal communities according to the soil physico-chemical properties. The common mycobiota contained 35 fungal species, including several species of Mortierella, Humicola, Solicoccozyma and Exophiala. Moreover, most of the identified fungal species (79%) were recorded for the first time in Colombian soils, thus adding important information on soil biodiversity regarding both Colombia and pear orchards.